How to maintain the same quality of HD video files filmed by the DCR-SR47sony Handycam?

When i make a video or data DVD of the already filmed scenes in the Handy-cam or from the files stored in the computer by the SONY PMB software i notice a considerable degradation in the video quality of the DVD. Actually the sony PMB lets you make a DVD only in SD (standard definition) while i need it to be the same quality if better is not possible.